“Double-vision display” refers to a display technology that different images displayed on one display screen can be seen at different positions at the same time, and if a distance between two positions is equal to a pitch of human eyes, it is just a “naked-eye 3D display”.
As shown in FIG. 1, an existing double-vision display device comprises a display panel 5 and a light splitting device, i.e., a double-vision device, arranged on a light exiting side of the display panel 5. The display panel 5 displays a two-dimensional image, and is divided into a plurality of first display regions 51 and second display regions 52 arranged alternately. Here, a “parallax barrier 91” is taken as a specific example of a double-vision device to illustrate. It can be seen from the diagrams that, the parallax barrier 91 comprises light shielding strips and light transmitting strips arranged alternately; by the parallax barrier 91, a viewer positioned in a first viewing region 81 on a left side of the display panel 5 only can see a part of the display panel 5 (i.e., the first display regions 51), while a viewer positioned in a second viewing region 82 on a right side of the display panel 5 only can see the other part of the display panel 5 (i.e., the second display regions 52), and a viewer in a crosstalk region 83 can see both of the first display regions 51 and the second display regions at a same time. In this way, as long as the first display regions 51 and the second display regions 52 display different images respectively, the different images can be seen in the first viewing region 81 and the second viewing region 82, respectively, thus achieving a double-vision display. Here, if a distance between the first viewing region 81 and the second viewing region 82 is equal to a pitch of human eyes, and a stereoscopic image pair having parallax is displayed in the first display regions 51 and the second display regions 52 respectively, then a left-eye image and a right-eye image having parallax can be seen by left and right eyes respectively, to achieve a naked-eye 3D display. Because the 3D display also belongs to a double-vision display, it will not be separately described hereinafter.
The double-vision device is to make light emitted from different positions (different display regions) of the display panel irradiate to different regions (different viewing regions), which has various forms, and besides the parallax barrier described above, the double-vision device may also be a lenticular lens.
However, no matter what kind of double-vision-device it is, the double-vision-device and the display panel must satisfy a specific positional relationship (i.e., an “alignment” must be performed) in order to achieve the double-vision display. If the alignment is not accurate, light from some display regions will enter other viewing regions (e.g., the light from the second display regions enter the first viewing region), there will be “crosstalk” in this viewing region, affecting a display effect. The alignment of an existing double-vision-device often employs a “red-green-image” method, i.e., two kinds of display regions of the display panel display red and green respectively, and then the double-vision device is gradually moved and viewers respectively positioned in the two viewing regions view the image; when pure red and pure green images are observed in the two viewing regions respectively, it proves an accurate alignment of the double-vision device, thus, the double-vision device may be fixed on the display panel (e.g., adhered to the display panel with adhesive).
However, the above alignment method depends on human eyes to observe and judge whether an alignment is accurate, so it is greatly affected by human factors, has poor accuracy, higher labor intensity, and low efficiency, and can be only implemented by specially-trained technical personnel.